Bug 913138 - Shut down imagelib at the end of layout shutdown. r=bsmedberg

Author: bholley

image/build/moz.build

@@ -4,6 +4,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+EXPORTS += [
+    'nsImageModule.h',
+]
+
 SOURCES += [
     'nsImageModule.cpp',
 ]

image/build/nsImageModule.cpp

@@ -4,6 +4,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "nsImageModule.h"
+
 #include "mozilla/ModuleUtils.h"
 #include "nsMimeTypes.h"
 
@@ -79,23 +81,29 @@ static const mozilla::Module::CategoryEntry kImageCategories[] = {
   { nullptr }
 };
 
-static nsresult
-imglib_Initialize()
+static bool sInitialized = false;
+nsresult
+mozilla::image::InitModule()
 {
   mozilla::image::DiscardTracker::Initialize();
   mozilla::image::ImageFactory::Initialize();
   mozilla::image::RasterImage::Initialize();
   mozilla::image::SurfaceCache::Initialize();
   imgLoader::GlobalInit();
+  sInitialized = true;
   return NS_OK;
 }
 
-static void
-imglib_Shutdown()
+void
+mozilla::image::ShutdownModule()
 {
+  if (!sInitialized) {
+    return;
+  }
   imgLoader::Shutdown();
   mozilla::image::SurfaceCache::Shutdown();
   mozilla::image::DiscardTracker::Shutdown();
+  sInitialized = false;
 }
 
 static const mozilla::Module kImageModule = {
@@ -104,8 +112,11 @@ static const mozilla::Module kImageModule = {
   kImageContracts,
   kImageCategories,
   nullptr,
-  imglib_Initialize,
-  imglib_Shutdown
+  mozilla::image::InitModule,
+  // We need to be careful about shutdown ordering to avoid intermittent crashes
+  // when hashtable enumeration decides to destroy modules in an unfortunate
+  // order. So our shutdown is invoked explicitly during layout module shutdown.
+  nullptr
 };
 
 NSMODULE_DEFN(nsImageLib2Module) = &kImageModule;

image/build/nsImageModule.h

@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsImageModule_h
+#define nsImageModule_h
+
+#include "nsError.h"
+
+namespace mozilla {
+namespace image {
+
+nsresult InitModule();
+void ShutdownModule();
+
+} /* namespace image */
+} /* namespace mozilla */
+
+
+#endif /* nsImageModule_h */

layout/build/nsLayoutModule.cpp

@@ -7,6 +7,7 @@
 
 #include "XPCModule.h"
 #include "mozilla/ModuleUtils.h"
+#include "nsImageModule.h"
 #include "nsLayoutStatics.h"
 #include "nsContentCID.h"
 #include "nsContentDLF.h"
@@ -1252,8 +1253,9 @@ LayoutModuleDtor()
   nsScriptSecurityManager::Shutdown();
   xpcModuleDtor();
 
-  // Layout depends heavily on gfx, so we want to make sure that gfx is shut
-  // down after all the layout cleanup runs.
+  // Layout depends heavily on gfx and imagelib, so we want to make sure that
+  // these modules are shut down after all the layout cleanup runs.
+  mozilla::image::ShutdownModule();
   gfxPlatform::Shutdown();
 }